tähtipilvi

Tähtipilvi is a Finnish term that translates to "star cloud" in English. It is most commonly used in astronomy to refer to a large, diffuse aggregation of stars that appears as a cloudy or nebulous mass in the sky. These objects are distinct from individual stars or tightly bound star clusters like globular clusters. Tähtipilvi can encompass a variety of celestial phenomena, including open star clusters that are loosely spread out, or regions of the Milky Way galaxy where the density of stars is particularly high, giving the appearance of a cloud. The term is not a formal astronomical classification but rather a descriptive one. Sometimes, very large and diffuse star clouds can be mistaken for nebulae, which are clouds of gas and dust, but a tähtipilvi specifically refers to a collection of stars. Historically, before telescopes provided a clearer view, such formations might have been perceived as indistinct patches of light, hence the "cloud" analogy.